Warm the olive oil in a large skillet over medium-high heat. Add the sliced mushrooms and diced onion, cooking until the mushrooms are nicely browned, about 5 to 7 minutes.
Stir in the minced garlic and continue cooking for another minute until fragrant.
Add the ground turkey to the pan, breaking it up as it cooks through, roughly 6 to 8 minutes. Drain any extra fat.
Mix in the Italian seasoning, salt, and pepper evenly.
Gradually add the fresh spinach, stirring until it has all wilted, approximately 2 to 3 minutes.
Lower the heat and blend in the heavy cream and grated Parmesan cheese, stirring until the cheese melts and the sauce becomes creamy. Serve hot right away.
